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javascript - Change image in HTML page every few seconds

I want to change images every few seconds, this is my code:

<?xml version = "1.0" encoding = "utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html xmlns = "http://www.w3.org/1999/xhtml">
   <head>
      <title>change picture</title>
      <script type = "text/javascript">

    function changeImage()
    {
    var img = document.getElementById("img");
    img.src = images[x];
    x++;

    if(x >= images.length){
        x = 0;
    } 
   var timerid = setInterval(changeImage(), 1000);
}   }
var images = [], x = 0;
images[0] = "image1.jpg";
images[1] = "image2.jpg";
images[2] = "image3.jpg";

      </script>
   </head>
   <body onload = "changeImage()">
 <img id="img" src="startpicture.jpg">
   </body>
</html>

My problem is its stuck on the first picture!

I also wanted to try flipping through the pictures with previous and next buttons but I have no idea how to do that.

See Question&Answers more detail:os

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1 Answer

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by (71.8m points)

As I posted in the comment you don't need to use both setTimeout() and setInterval(), moreover you have a syntax error too (the one extra }). Correct your code like this:

(edited to add two functions to force the next/previous image to be shown)

<!DOCTYPE html>

<html>
   <head>
      <title>change picture</title>
      <script type = "text/javascript">
          function displayNextImage() {
              x = (x === images.length - 1) ? 0 : x + 1;
              document.getElementById("img").src = images[x];
          }

          function displayPreviousImage() {
              x = (x <= 0) ? images.length - 1 : x - 1;
              document.getElementById("img").src = images[x];
          }

          function startTimer() {
              setInterval(displayNextImage, 3000);
          }

          var images = [], x = -1;
          images[0] = "image1.jpg";
          images[1] = "image2.jpg";
          images[2] = "image3.jpg";
      </script>
   </head>

   <body onload = "startTimer()">
       <img id="img" src="startpicture.jpg"/>
       <button type="button" onclick="displayPreviousImage()">Previous</button>
       <button type="button" onclick="displayNextImage()">Next</button>
   </body>
</html>

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